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                                            As of April 27, 1995
         
         
         
         Bird Corporation
         and Bird Incorporated
         980 Washington Street
         Suite 120
         Dedham, Massachusetts  02026
         
                   Re:  Asset Purchase Agreement dated as of September 23, 
                        1994, as amended (the "Asset Purchase Agreement"), 
                        among Bird Corporation, Bird Incorporated and 
                        Jannock, Inc.                                     
                        --------------------------------------------------

         Ladies and Gentlemen: 
         
                   Pursuant to Section 1.03 of the Asset Purchase Agreement, 
         Jannock, Inc., a Delaware corporation ("Buyer"), has the option 
         (the "Option"), exercisable on or before noon on April 28, 1995, to 
         acquire from Bird Incorporated, a Massachusetts corporation 
         ("Seller"), all the outstanding capital stock (the "Holding Stock") 
         of Bird-Kensington Holding Corp., a Delaware corporation 
         ("Holding").  Terms defined in the Asset Purchase Agreement are 
         used herein as therein defined. 
         
                   Buyer has advised Seller that it is willing to exercise 
         the Option to acquire the Holding Stock on the Kensington Closing 
         Date, subject to satisfaction of the conditions set forth in 
         Sections 8.06 through 8.14 and Section 13.02 of the Asset Purchase 
         Agreement, only upon the further condition that the Asset Purchase 
         Agreement be amended and supplemented in the manner hereinafter 
         provided.  Seller has advised Buyer that it desires that Buyer 
         exercise the Option and acquire the Holding Stock. 
         
                   Accordingly, Parent, Seller and Buyer, intending to be 
         legally bound hereby, agree that the Asset Purchase Agreement shall 
         be amended and supplemented as follows: 
         
                   1.  On or before to the Kensington Closing Date, Seller 
         (a) shall have caused Kensington Partners (i) to make the revisions 
         and adjustments in its financial statements as of March 31, 1995 
         and for the periods then ended specified on Schedule 1 hereto and 
         (ii) pay all Federal, State and local taxes, including withholding, 
         sales and unemployment taxes, and all related interest and 
         penalties payable by Kensington Partners with  respect to all 
         periods ending on or before March 31, 1995, including any amounts 
         being contested ("Prior Period Taxes"), (iii) to pay all 
         unsatisfied judgments or other liens set forth on Part C of 
         Schedule 2 hereto (Part C Liens") recorded on the books of 
         Kensington Partners, (iv) to record on the books of Kensington 
         Partners, add to Schedule 1 hereto and pay any liabilities secured 
         by Part C Liens which Seller reasonably determines are appropriate 
         and which are not currently recorded on such books and (v) to pay 
         all amounts of rent due under leases of the Kensington artners 
         Facility securing the Financings and (b) shall have invested 
         sufficient funds in the equity of Kensington Partners such that the 
         net partnership equity of Kensington Partners, computed in 

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         accordance with generally accepted accounting principles as of 
         March 31, 1995 and following the revisions and adjustments referred 
         to herein, shall not be less than $1,150,000; provided, however, 
         that the aggregate amount which Seller shall be required to invest 
         in Kensington Partners pursuant to this paragraph 1 between the 
         date hereof and the Kensington Closing Date shall not exceed 
         $5,100,000 and all payments required to be made pursuant to this 
         paragraph 1 shall be made out of such funds so invested.  Following 
         the Kensington Closing Date, any refunds of any amounts paid by 
         Kensington Partners in respect of Prior Period Taxes shall be 
         promptly paid to Seller.  Seller and Parent shall jointly and 
         severally indemnify and hold harmless Buyer from and against any 
         and all Damages suffered by Buyer resulting from, arising out of, 
         or in connection with any claims in respect of Prior Period Taxes 
         and liabilities secured by Part C Liens.
         
                   2.  On or before the Kensington Closing Date, Seller will 
         cause the interest of Kensington Partners in the partnership, and 
         the rights and obligations of Kensington Partners under the 
         Partnership Agreement, referred to in Item K.4. of Schedule 4.17 to 
         the Asset Purchase Agreement and the interest of Holding in the 
         partnership, and the rights and obligations of Holding under the 
         Partnership Agreement, referred to in Item K.5. of Schedule 4.17 of 
         the Asset Purchase Agreement, to be transferred to and assumed by 
         Seller.  Further, on or before the Kensington Closing Date, Seller 
         will cause the rights and obligations of Kensington Partners under 
         the agreements referred to in Items F.3. and F.4. of Schedule 4.17 
         to the Asset Purchase Agreement to be transferred to and assumed by 
         Seller.
         
                   3.  In addition to the conditions set forth in 
         Sections 8.06 through 8.14 and Section 13.02 of the Asset Purchase 
         Agreement, the obligation of Buyer to pay the Additional Purchase 
         Price and acquire the Holding Stock shall be subject to the due 
         execution and delivery of the following agreements, in form and 
         substance reasonably satisfactory to Buyer, by the following 
         parties on or before the Kensington Closing Date: 
         
                        a.  A supply agreement between Kensington Partners 
                   and Jones & Brown, Inc. (""J&B") covering the annual 
                   purchase of windows by J&B from Kensington Partners at a 
                   volume reasonably satisfactory to Buyer, which supply 
                   agreement shall have a term of not less than five years.
                   
                        b.  An agreement of sale between Holding and ZES, 
                   Inc. pursuant to which ZES, Inc. shall have sold all of 
                   the interest of ZES, Inc. in Kensington Partners to 
                   Holding. 
                   
                        c.  An amendment to the lease agreement ("Lease 
                   Agreement") between Lila Snyder ("Mrs. Snyder") and 
                   Kensington Partners relating to the Kensington Partners 
                   Facility pursuant to which (i) the rent thereunder is 
                   fixed in an amount equal, from time to time, to the 
                   payments due under the four financings listed on Part A 
                   of Schedule 2 hereto (the "Financings") secured by the 
                   Kensington Partners Facility, (ii) Mrs. Snyder grants 
                   Kensington Partners an option to acquire the Kensington 
                   Partners Facility and (iii) Kensington Partners is 
                   granted the right to cure landlord defaults under the 
                   Financings, including the failure to pay taxes, and to 
                   pay rent directly to the Financing parties.
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                        d.  Assignments executed by J&B or ZES, Inc., as 
                   appropriate, transferring and assigning to Kensington 
                   Partners all right, title and interest of the assigning 
                   party in and to (i) the trademarks listed on 
                   Schedule 4.25 to the Asset Purchase Agreement, (ii) the 
                   lease dated April 1, 1992 between Regency Management 
                   Services and J&B regarding heat mirror equipment, and 
                   (iii) each other agreement reflected on Part B of 
                   Schedule 2 hereto and each other asset reflected on the 
                   books of Kensington Partners on the Kensington Closing 
                   Date as an asset of Kensington Partners and not 
                   heretofore transferred to it. 
                   
                        e.  Consents to assignment by (i) Amplicon, Inc. 
                   with respect to the lease agreement dated as of 
                   September 20, 1993 between Amplicon, Inc. and Kensington 
                   Partners, (ii) Southwall Technologies, Inc. ("Southwall") 
                   with respect to the Value-Added Reseller Agreement dated 
                   as of May 9, 1991 between Southwall and Kensington 
                   Manufacturing Co., and (iii) the lessors under the 
                   equipment leases listed as items 1, 2, 6 and 7 on Part B 
                   of Schedule 2 hereto.
                   
                        f.  Releases (and UCC-3's) or similar documents 
                   reasonably satisfactory to Buyer executed by each person 
                   who holds a lien against the Kensington Partners 
                   Facility, other than the parties to the Financings and 
                   the lessors (or their assigns) under the equipment leases 
                   listed in Part B of Schedule 2 hereto, including without 
                   limitation each person who holds a Part C Lien; PROVIDED, 
                   HOWEVER, that the parties hereto acknowledge and agree 
                   that any and all payments required to satisfy any 
                   judgments and liens described in this paragraph 3.f shall 
                   be made only out of the funds invested by Seller in 
                   Kensington Partners pursuant to paragraph 1 hereof.
                   
                        g.  A computer support agreement between Kensington 
                   Partners and J&B pursuant to which J&B agrees to provide 
                   the computer services to Kensington Partners which it is 
                   currently providing for a period of 12 months following 
                   the Kensington Closing Date at a cost of $12,000 per 
                   month.
                   
                        h.  An agreement by ZES, Inc., J&B, Mrs. Snyder and 
                   Barry D. Snyder (individually, a "Snyder Party" and 
                   collectively, the "Snyder Parties") in which each Snyder 
                   Party (i) releases Kensington Partners, Holding and Buyer 
                   from and against any liability each may have to such 
                   Snyder Party other than any such liability, in the case 
                   of Mrs. Snyder, under the Lease Agreement, as amended as 
                   contemplated in clause(c) above, in the case of J&B, 
                   under the agreements referred to in clauses(a) and (g) 
                   above and, in the case of each of the Snyder Parties, 
                   accounts payable and other liabilities incurred by 
                   Kensington Partners in the ordinary course of business 
                   and reflected on the Kensington Closing Balance Sheet and 
                   (ii) agrees not to compete with Kensington Partners or 
                   Holding in the manufacture of polyvinyl chloride
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                   replacement windows such noncompetition agreement to be 
                   on terms reasonably acceptable to Buyer.
         
                   4.  On or before the Kensington Closing Date, the Seller 
         shall take such action as shall be necessary to cause the condition 
         set forth in Section 8.14 of the Asset Purchase Agreement to be 
         satisfied including but not limited to the execution, delivery and 
         filing of appropriate UCC-3 termination statements evidencing the 
         satisfaction of such condition.
         
                   5.  The liabilities and obligations of Kensington 
         Partners or Holding incurred in connection with or resulting from 
         (a) the matters or agreements referred to in, Schedule 4.16 and 
         Schedule 4.17, Items F.3., F.4., K.4. and K.5., and (b) any other 
         liabilities of Kensington Partners or Holding incurred in 
         connection with or resulting from the interest of either in North 
         American Installation Company, Quantum II Partners ("Quantum II"), 
         Permalite and Window Systems of Cleveland (the "Third Party 
         Ventures") shall, for purposes of Article X of the Asset Purchase 
         Agreement, be deemed Retained Liabilities; PROVIDED, HOWEVER, that 
         "normal and customary product warranty claims for windows" 
         manufactured and sold by Kensington Partners in connection with the 
         activities of the Third Party Ventures shall be deemed Assumed 
         Liabilities and PROVIDED FURTHER that the term "normal  and 
         customary warranty claims for windows" shall exclude all claims 
         relating to the installation by any Third Party Venture of any 
         windows and all claims relating to the manufacture or sale of 
         Quantum II products not manufactured to customer specifications and 
         supplied by Kensington Partners to NewPro, Ambassador, Permalite or 
         Window Systems of Cleveland.  Buyer shall cause Holding to 
         cooperate with Seller in connection with the Retained Liabilities 
         in this paragraph 5 and make available to Seller or its designee 
         replacement parts on commercially reasonable terms and prices.  The 
         penultimate sentence of Section 10.04(c) of the Asset Purchase 
         Agreement shall not apply to the Retained Liabilities referred to 
         in this paragraph or to the breach by Seller of its covenants 
         contained in paragraphs 1, 2 and 4 of this letter agreement. 
         
                   6.  Seller and Parent agree to join with Buyer in making 
         an election under section 338(h)(10) of the Internal Revenue Code 
         of 1986 (the "Code") and under any comparable provisions of state, 
         local, or foreign law with respect to the purchase of the Holding 
         Stock.  As promptly as practicable following delivery of the 
         Kensington Closing Balance Sheet, Buyer shall execute and deliver 
         to Parent five copies of Internal Revenue Service Form 8023, a 
         preliminary draft of which Form shall have been provided to, and 
         reviewed and approved by, Parent at least 5 days prior to the 
         Kensington Closing Date.  Unless such Form differs materially from 
         the draft thereof previously provided to Parent, Parent shall 
         promptly execute and redeliver such Form to Buyer.  Seller and 
         Parent shall comply with all of the requirements of section 
         338(h)(10) of the Code and the Treasury Regulations thereunder. 
         Seller and Parent shall take no action which is inconsistent with 
         the requirements for filing the election under section 338(h)(10) 
         of the Code and the applicable Treasury Regulations.  Seller and 
         Parent agree that to the extent that an election similar to an 
         election under section 338(h)(10) of the Code is optional under any 
         state, local, or foreign law, Seller and Parent shall join in any 
         such election as requested in writing by Buyer. 
         
                   7.  Within 30 days following the Kensington Closing Date, 
         Buyer shall deliver to Seller a balance sheet, prepared in 

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         accordance with the generally accepted accounting principles 
         consistently applied, reflecting the assets and liabilities of 
         Holding as of the Kensington Closing Date (the "Kensington Closing 
         Balance Sheet").  The preparation of the Kensington Closing Balance 
         Sheet, objections thereto and the resolution of disputes with 
         respect thereto shall be dealt with in the manner contemplated by 
         Sections 3.01 and 3.02 of the Asset Purchase Agreement with respect 
         to the Closing Balance Sheet which provisions are hereby included 
         herein MUTATIS MUTANDIS except that  appropriate changes shall be 
         made to reflect the fact that Buyer shall prepare the Kensington 
         Closing Balance Sheet, the Kensington Closing Balance Sheet shall 
         not be audited and the limitations contained in Section 3.02(b) 
         shall not be applicable.  In the event that the amount of net 
         equity reflected with Kensington Closing Balance Sheet is less than 
         $1,050,000, Seller shall pay to Buyer such difference and in the 
         event such amount is more than $1,250,000 Buyer shall pay to Seller 
         such difference. 
         
                   8.  Upon execution and delivery of this letter agreement 
         by Seller, Parent and Buyer, this letter agreement shall constitute 
         the exercise by Buyer of the Option, subject to the satisfaction on 
         or before the Kensington Closing Date of the conditions set forth 
         in the Asset Purchase Agreement, as amended and supplemented 
         hereby, required to be satisfied on or before such Date. 
         
                   9.  The parties shall take such steps as are necessary to 
         cause the Kensington Closing Date to occur on Tuesday May 30, 1995 
         with effect from 7:00 a.m. on that date or as promptly as 
         practicable thereafter. 
         
                   If the foregoing accurately represents the understanding 
         of the parties to the Asset Purchase Agreement with respect to the 
         subject matter hereof, please execute and return the enclosed 
         copies of this letter agreement, whereupon it shall become a 
         binding agreement among us and a binding amendment and supplement 
         to the Asset Purchase Agreement.  The parties hereto hereby confirm 
         that the Asset Purchase Agreement, as amended and supplemented 
         hereby, remains in full force and effect. 
         
                                            Very truly yours,
                                            
                                            Jannock, Inc.
                                            
                                            By                            
                                              --------------------------------
                                              Michael A. Risso
                                              President
         Agreed to:
         
         Bird Corporation
         
         By:                           
            ----------------------------
            Joseph D. Vecchiolla
            Chairman and Chief Executive Officer
         
         Bird Incorporated
         
         By:                           
            ----------------------------
            Joseph D. Vecchiolla
            Chairman and Chief Executive Officer